Drill press feed control reductor



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Patented May 4, 1954 NITED STATES ATENT OFFICE 1 Claim. l

rPhe present invention relates to drill presses and light duty machines and gear drive units therefor, and particularly to a reductor gear box for such machines.

The main object of my invention is to provide drill presses and light duty machines with means for reducing the speed and increasing the torque thereof to such an extent that they may be used for heavy cutting and/or drilling operations of great accuracy and delicate detail under perfect control.

Another object is to provide means for converting an ordinary drill press into a light vertimilling machine.

A further object is to improve performance of drill presses by reducing twist drill breakage to a minimum when a drill breaks through a work piece, due to uneven pressure exerted by hand.

fin ancillary object is to increase safety in operation and be less likely to pull upon the operators arm when the drill passes through the work and not so likely to catch in the work piece and spin it around with resulting danger of inflicting injury.

It is even an object to have a drill press thus equipped to facilitate large bores being drilled while using iiy cutters.

A practical object is of course to widen the cope and utility of a drill press and thus render it more useful than normally and therefor more fully use the maior portion of the time work is to be performed by machine.

Other objects and advantages of my invention will appear in greater detail as the specification proceeds.

In order to facilitate ready comprehension of this invention for a proper appreciation of the salient features thereof, the invention is illustrated on the accompanying drawings forming part hereof, and in which:

Figure l is a side elevation of a drill press equipped with means embodying the invention in a practical form;

Figure 2 is a fragmentary front elevation of the same drill press with the invention applied thereto;

Figure 3 is a transverse section as taken on line 3-3 in Figure 1;

Figure i is another transverse section taken on line i-ll in Figure 3;

Figure 5 is a further section as taken on line 5- in Figure 4.

Throughout the views, the same reference numerals indicate the same or like parts.

Drill presses and other light duty machines and machine tools are usually limited to specific operations for which they are built, simply because they run at rather high speeds. This prevents such machines from doing any heavy drilling, milling or cutting, as they cannot carry such loads, even how desirable this would be.

Upon considering this problem, it has occurred to me that such light duty machines should be equipped with means for stepping down their speed of operation in efficient manner so that the load can be increased and the feeding can be retarded for cutting or drilling into the work piece operated upon. As a result, I have succeeded in producing a reductor device for such machines that increases their power, scope and utility along the lines already mentioned, as will now be set forth in detail in the following.

Hence, in the practice of my invention, and referring also again to the drawings, a typical drill press, generally indicated at l, primarily includes a base S having a fixed post 9, a vertically adjustable drill table I supported thereon, and a drill head il secured upon the upper portion of this post. A motor l2 is secured in place upon the rear of the head I i, while a drill chuck i3 is mounted upon drill shaft It rotatably supported in drill head ii, with a vertically slidable bearing i5 therefor adjustable in said head for feeding the chuck up or down. To this bearing is secured the limit gage rod i6 having the limit nuts il adjustable on the upper threaded portion of rod it to form a stop for the downward travel of the chuck in more or less conventional manner.

Upon head i i is also xed the horizontal bearing i8 for a feed shaft I9, Figures 2 and 3, having a transverse hole 2t therein for the conventional handle rod (not shown) which for the present purpose is temporarily removed, so that the device embodying the invention proper may be mounted in position on the press.

The press head H is provided with a side stud 2i xed in horizontal position above feed shaft i9 and parallel therewith, the outer right end of this stud being threaded. The novel feed reductor device embodying the invention as such is generally indicated at 22 and includes a casing or frame 23 of substantially rectangular forni having one end thereof closed by a plate or block 2li secured in position by screws 25 (one shown) and having an integral hub 2t extending therefrom and forming a bearing for a hollow rotary shell 2. Upon the outer end of the shell is formed a wide flange 28 having a plurality of set screws 29, 29 therein serving to fix the shell upon the feed shaft I9 upon which this shell fits closely. The inner end of this shell has an integral stub shaft 30 with a reduced threaded end 3l fitted with a retaining nut 32. Upon stub shaft 3B is mounted a worm gear 33 retained in place by nut 32 and positively rotated by the shaft by means of a key 34 extending into the shaft and into slot 35 in the gear. Within casing 23, the hub 26 continues inwardly to form a bearing stop or guide 36 for the worm gear to prevent axial shifting of this gear.

With worm gear 33 meshes a worm 3'! mounted on a Worm shaft 38 supported rotatably in a pair of bearings 39, 40 secured within casing 23 to the closing plate 24 by means of screws 4l (one shown). Upon this worm shaft are secured a pair of exterior collars 42, 43 by means of set screws 44, 45, while upon one end of the shaft is secured the hand wheel 46 retained in place by means of a nut 4l screwed upon the threaded reduced end 4S of the shaft. Preferably, the bearings 39 and 4S are provided with bushings 49 and 50, while the worm 31 is retained on its shaft 38 for positive rotation therewith by means of a key I, best seen in Figure 3. The bushings may be retained in place by screws 52 or the like.

Upon the outside of plate 24 is secured a bracket 53 by a screw 54 that is screwed into this plate and at its upper end has an open slot 55 fitting the anchoring stud 2l and being secured to the latter by nuts 56, Ei'l, to prevent rotation of the device as a whole when the hand wheel is turned. The device as a whole replaces the usual handle or rod that ordinarily fits in hole 23 of feed shaft I9.

When the drill is provided in its chuck with the desired heavy duty tool and motor i2 is started, rotation of hand wheel 45 rotates worm 37 and this gradually rotates worm gear 33 and with it the feed shaft i9. This feed shaft feeds the chuck i3 downward very slowly at reduced speed, due to the presence of Worm 37 and worm gear 33, but with greatly increased force, while bracket 53 and the anchoring stud 2| prevent the casing 23 from rotating or becoming displaced with respect to the drill press as a whole. The device is thus a reducing attachment for the feeding of the chuck held tool slowly and powerfully so that milling operations may beperformed or heavy drilling done on the machine.

When the drill press is to be used for normal light drilling, the reductor attachment may be removed readily by simply releasing one nut 5l from bracket 53 and set screws 29, 29 from gripping feed shaft i9, and the device then lifted free. The handle rod may then be restored to hole 2i) in the feed shaft and the press is wholly coventional again.

Manifestly, variations may be resorted to, and parts and features may be modified or used without others within the scope of the appended claim.

Having now fully described my invention, I claim:

A drill press reducing gear feed device for a drill press including a head and having a feed shaft adapted to feed a drill chuck shaft vertically, the said reducing gear feed device including a frame open at one side, a plate adapted to close the open side of the said frame and extending into an integral hub, a hollow rotary shell rotatably disposed in the said hub and receiving one end of the said feed shaft, means for securing the said hollow rotary shell to the said feed shaft for common rotation, the said hollow rotary shell having an integral stub shaft with a reduced threaded end, a worm gear mounted on the said stub shaft, key means on the said stub shaft for rotation of the said worm gear therewith, the said hub extending towards the said Worin gear to form a stop for the latter and to prevent axial movement thereof, a worm mounted on worm shaft within the said frame and meshing the said worm gear, a hand-wheel secured to one of the said worm shaft for rotation cf the worm and of the worm gear together with the said feed shaft, a bracket secured to the said plate, one end of the said bracket being secured to the said head of the press, the said bracket being adapted to prevent rotation of the said frame with the said feed shaft.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 309,073 March Dec. 9, 1834 2,529,597 Dath Nov. 4, 1950 

